The present invention relates to a data communication system, and more specifically to a method for granting a request to authorized data terminal users accessing from any locations to a central station.
In conventional data communication systems in which requests for access are granted only to authorized terminal users, the telephone numbers of such authorized users and their passwords are registered in the central station and the users are requested to send the associated passwords to the central station for verification of the password and if the password is verified the central station proceeds to call back the calling party by dialing the registered telephone number.
Advances in electronic technolgy have resulted in compact terminal equipments which can be hand carried to any location which is accessible through a telephone switching network to a desired central station. However, the telephone line terminal of the new location is not necessarily registered in the central station and the latter's callback attempt thus fails to reestablish a connection.